A new method for measurement of subcoracoid outlet and its relationship to rotator cuff pathology at MR arthrography

OBJECTIVE

Orthopaedic surgical studies have shown that variations in the vertical distance between the tip of the coracoid process and the supra-glenoid tubercle alter the shape of the subcoracoid outlet. Our objective was to measure the vertical distance between the coracoid tip and the supra-glenoid tubercle (CTGT) on MR and to assess whether this showed better correlation with rotator cuff pathology compared with the axial coraco-humeral distance.

MATERIALS AND METHODS

A retrospective review was performed of 100 consecutive shoulder MR arthrograms. Vertical distance between the coracoid tip and the supraglenoid tubercle was measured in the sagittal oblique plane. Separate assessment was then made of tendon pathology of the subscapularis, supraspinatus and long head of biceps tendons. Axial coraco-humeral distance was then measured. Correlation between tendon abnormalities and the two measurements was then made.

RESULTS

Of the 100 cases, 42 had subscapularis tendon lesions, 21 had lesions of the long head of biceps and 53 had supraspinatus tendon lesions. Mean vertical distance from the coracoid tip to supraglenoid tubercle was greater in those with lesions of any of these tendons and was statistically significant for the supraspinatus group (P = 0.005). Reduced axial coraco-humeral distance was also seen in patients with tendinopathy, although with less statistically significant difference (p = 0.059).

CONCLUSION

Our results support orthopaedic studies that have shown that the vertical distance between the coracoid tip and the supraglenoid tubercle increases the incidence and risk of rotator cuff disease by altering the shape of the subcoracoid outlet.

MRI of inflammatory spondyloarthropathy following traumatic cauda equina syndrome

BACKGROUND CONTEXT

Spondyloarthropathy has been described radiographically in patients following paralysis from spinal cord trauma. Onset of these findings after cauda equina syndrome have not been reported previously. Furthermore, the magnetic resonance documentation of its early evolution has not been recorded.

PURPOSE

We report a case of early-onset spondyloarthropathy shown by magnetic resonance imaging (MRI) in a patient with cauda equina syndrome due to bilateral sacral insufficiency fractures.

STUDY DESIGN

Unique case study review, one case.

METHODS

Review of the clinical case notes and imaging including initial and subsequent MR imaging.

RESULTS

The initial MRI of the lumbosacral spine showed bilateral sacral insufficiency fractures with a kyphotic deformity. The vertebral bodies were normal on the initial computed tomography and MRI studies, which did not reveal pre-existing features of sacroiliitis. The second MRI performed 5 months later clearly showed spondylitis at multiple vertebral levels with partial resolution 18 months post injury.

CONCLUSION

Spondyloarthropathy in patients with paralysis due to spinal cord injury is well documented in the English language literature, but until now this has not been demonstrated by MRI. It is a rare complication of traumatic cauda equina syndrome that commences soon after the traumatic event and can resolve spontaneously.

SAPHO: What radiologists should know

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) is an umbrella acronym for inflammatory clinical conditions whose common denominator is aseptic osteoarticular involvement with characteristic skin lesions. It involves all ages, can involve any skeletal site, and has variable imaging appearances depending on the stage/age of the lesion and imaging method. It mimics important differentials including infection and neoplasia. Awareness of the imaging features, especially in the spine, facilitates early diagnosis, prevents repeated biopsies, and avoids unnecessary surgery, while initiating appropriate treatment.

The spine in Paget's disease

Paget's disease (PD) is a chronic metabolically active bone disease, characterized by a disturbance in bone modelling and remodelling due to an increase in osteoblastic and osteoclastic activity. The vertebra is the second most commonly affected site. This article reviews the various spinal pathomechanisms and osseous dynamics involved in producing the varied imaging appearances and their clinical relevance. Advanced imaging of osseous, articular and bone marrow manifestations of PD in all the vertebral components are presented. Pagetic changes often result in clinical symptoms including back pain, spinal stenosis and neural dysfunction. Various pathological complications due to PD involvement result in these clinical symptoms. Recognition of the imaging manifestations of spinal PD and the potential complications that cause the clinical symptoms enables accurate assessment of patients prior to appropriate management.

Quantitative 3D MR evaluation of autologous chondrocyte implantation in the knee: feasibility and initial results

OBJECTIVE

To evaluate the feasibility of quantitative magnetic resonance imaging (MRI) based follow-up of cartilage volumetric data in patients after autologous chondrocyte implantation (ACI). To provide results from a 1-year follow-up study.

METHODS

From 21 ACI patients sagittal FS 3D FLASH (50/11/30; 0.6x0.6x1.5mm(3)) MRI knee data sets were obtained pre and 1-year post-ACI surgery in the femoral condyles. After semi-automated segmentation and 3D reconstruction of the cartilage plates, cartilage volume, mean thickness and size of the cartilage-bone interface were calculated. Susceptibility artifacts were evaluated in all, intra-observer reproducibility was evaluated in six of the patients. Volumetric parameters were compared during follow-up and sensitivity to change was assessed for the total femur vs the separately evaluated medial/lateral portions of the femur.

RESULTS

Reproducibility error (coefficient of variation %) was 3.9%/4.4% for the med./lat. tibial and 5.1% for the femoral cartilage volume. Susceptibility artifacts led to the exclusion of three out of the 21 patients, but were moderate in the remaining 18 patients, not preventing reproducible segmentation. In contrast to lack of significant change in the (non-operated) tibiae, a mean 6% increase of volume and thickness in the treated femora (P<0.001 Wilcoxon) relative to the pre-OP data was observed. Sensitivity to change for the femur ranged from 0.74 to 2.60 for cartilage volume and thickness and was improved when evaluating only the treated portion of the femur in contrast to the total femur.

CONCLUSION

Our data indicate that despite postoperative susceptibility artifacts quantitative evaluation of cartilage volumetric parameters can be performed in ACI patients. The technique is able to describe changes of these parameters over 1 year. Volumetric follow-up may help to identify altered disease progression.

Imaging of acute cervical spine injuries: review and outlook

Advances in imaging technology have been successfully applied in the emergency trauma setting with great benefit providing early, accurate and efficient diagnoses. Gaps in the knowledge of imaging acute spinal injury remain, despite a vast wealth of useful research and publications on the role of CT and MRI. This article reviews in a balanced manner the main questions that still face the attending radiologist by embracing the current and evolving concepts to help define and provide answers to the following; Imaging techniques -- strengths and weaknesses; what are the implications of a missed cervical spine injury?; who should be imaged?; how should they be imaged?; spinal immobilisation -- help or hazard?; residual open questions; what does all this mean?; and what are the implications for the radiologist? Although there are many helpful guidelines, the residual gaps in the knowledge base result in incomplete answers to the questions posed. The identification of these gaps in knowledge however should act as the initiating stimulus for further research. All too often there is a danger that the performance and productivity of the imaging modalities is the main research focus and not enough attention is given to the two fundamental prerequisites to the assessment of any imaging technology -- the clinical selection criteria for imaging and the level of expertise of the appropriate clinician interpreting the images.

MR imaging of pseudosarcoma in Paget's disease of bone: a report of two cases

Pseudosarcoma is a rare manifestation of Paget's disease of bone. We report the MR imaging of two cases highlighting the difficulties in diagnosis. One of the cases is the first time this condition has been described outside the long bones of the lower limb.